全文获取类型
收费全文 | 50720篇 |
免费 | 4276篇 |
国内免费 | 397篇 |
专业分类
耳鼻咽喉 | 810篇 |
儿科学 | 1098篇 |
妇产科学 | 974篇 |
基础医学 | 8092篇 |
口腔科学 | 774篇 |
临床医学 | 4748篇 |
内科学 | 10300篇 |
皮肤病学 | 1672篇 |
神经病学 | 4392篇 |
特种医学 | 2795篇 |
外科学 | 5987篇 |
综合类 | 520篇 |
现状与发展 | 1篇 |
一般理论 | 16篇 |
预防医学 | 3268篇 |
眼科学 | 1341篇 |
药学 | 4284篇 |
中国医学 | 424篇 |
肿瘤学 | 3897篇 |
出版年
2023年 | 229篇 |
2022年 | 612篇 |
2021年 | 1342篇 |
2020年 | 736篇 |
2019年 | 1146篇 |
2018年 | 1301篇 |
2017年 | 1013篇 |
2016年 | 1494篇 |
2015年 | 1934篇 |
2014年 | 2283篇 |
2013年 | 2705篇 |
2012年 | 3851篇 |
2011年 | 3751篇 |
2010年 | 2274篇 |
2009年 | 1892篇 |
2008年 | 2679篇 |
2007年 | 2668篇 |
2006年 | 2412篇 |
2005年 | 2288篇 |
2004年 | 1966篇 |
2003年 | 1739篇 |
2002年 | 1608篇 |
2001年 | 996篇 |
2000年 | 966篇 |
1999年 | 826篇 |
1998年 | 386篇 |
1997年 | 356篇 |
1996年 | 304篇 |
1995年 | 289篇 |
1994年 | 238篇 |
1993年 | 264篇 |
1992年 | 601篇 |
1991年 | 630篇 |
1990年 | 543篇 |
1989年 | 598篇 |
1988年 | 582篇 |
1987年 | 574篇 |
1986年 | 498篇 |
1985年 | 496篇 |
1984年 | 392篇 |
1983年 | 326篇 |
1982年 | 242篇 |
1981年 | 221篇 |
1980年 | 201篇 |
1979年 | 296篇 |
1978年 | 257篇 |
1977年 | 183篇 |
1974年 | 204篇 |
1973年 | 223篇 |
1972年 | 175篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Usefulness of optical coherence tomography to detect central serous chorioretinopathy in monkeys 下载免费PDF全文
Hyun‐Kyu Park Woori Jo Hyun‐Ji Choi Bongcheol Kim Gilnam Lee Jeongbeob Seo Suk Young Cho Choung‐Soo Kim Eun Kyung Choi Jung Jin Hwang Joo Yong Lee Young Hee Yoon Woo‐Chan Son 《Journal of applied toxicology : JAT》2015,35(2):199-204
Many systemic drugs can induce ocular toxicity and several ocular side‐effects have been identified in clinical studies. However, it is difficult to detect ocular toxicity in preclinical studies because of the lack of appropriate evaluation methods. Optical coherence tomography (OCT) is useful because it can provide real‐time images throughout a study period, whereas histopathology only provides images of sacrificed animals. Using OCT alongside histopathology, attempts were made to find effective approaches for screening of drug‐induced ocular toxicity in monkeys. Such approaches could be used in preclinical studies prior to human trials. Six male cynomolgus monkeys (Macaca fascicularis Raffles) were orally administered one of six candidate MAPK/ERK kinase (MEK) inhibitors. Central serous chorioretinopathy, a known side‐effect of such inhibitors, was identified in four monkeys by OCT. Artifacts generated during tissue processing meant that histopathology could not detect edematous changes. Thus, OCT is a useful tool to detect ocular toxicity which cannot be detected by histopathology in preclinical studies. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
992.
Characteristic molecular and proteomic signatures of drug‐induced liver injury in a rat model 下载免费PDF全文
993.
Elyssa?BesenEmail author Amanda?E.?Young William?S.?Shaw 《Journal of occupational rehabilitation》2015,25(1):25-37
Purpose The aim of this paper is to develop and test a model of direct and indirect relationships among individual psychosocial predictors of return-to-work (RTW) outcomes following the onset of low back pain (LBP). Methods We utilize secondary analysis of a larger study of adults seeking treatment for work-related LBP with recent onset. In total, 241 participants who completed a baseline survey, a short follow-up survey, and a longer follow-up survey after 3 months were included in our analyses. The participants were required to have LBP with onset of less than 14 days, be 18 years or older, and be fluent in English or Spanish. The analyses utilized structural equation models to test the direct and indirect relationships among the variables and RTW outcomes at 3 months. Results Our results indicated a good fit for our model (χ2 = 69.59, df = 45, p < .05; RMSEA = .05; CFI = .95; WRMR = .61). Pain, catastrophizing, fear-avoidance beliefs, organizational support, and RTW confidence were all found to have indirect relationships with the outcomes. RTW confidence and RTW expectations were found to have direct relationships with the outcomes. Conclusions The process of returning to work after an episode of LBP is a complex process involving many interrelated factors. Understanding the relationships among critical individual factors in the RTW process may be important for the treatment and rehabilitation of those with LBP. Results suggest that if injured workers are struggling with fear avoidance, pain catastrophizing and confidence issues, they might benefit from the application of cognitive behavioral therapy techniques. 相似文献
994.
995.
Wan Beom Park Ranawaka A.P.M. Perera Pyoeng Gyun Choe Eric H.Y. Lau Seong Jin Choi June Young Chun Hong Sang Oh Kyoung-Ho Song Ji Hwan Bang Eu Suk Kim Hong Bin Kim Sang Won Park Nam Joong Kim Leo Lit Man Poon Malik Peiris Myoung-don Oh 《Emerging infectious diseases》2015,21(12):2186-2189
We investigated the kinetics of serologic responses to Middle East respiratory syndrome coronavirus (MERS-CoV) infection by using virus neutralization and MERS-CoV S1 IgG ELISA tests. In most patients, robust antibody responses developed by the third week of illness. Delayed antibody responses with the neutralization test were associated with more severe disease. 相似文献
996.
Elizabeth Marlow PhD C‐FNP Marcianna Nosek PhD MPH CNM CNL Yema Lee Earthy Young Alejandra Bautista Finn Thorbjørn Hansen PhD 《Nursing philosophy》2015,16(1):19-28
This paper describes the first phase of an ongoing education and research project guided by three main intentions: (1) to create opportunities for phronesis in the classroom; (2) to develop new understandings about phronesis as it relates to nursing care generally and to caring for specific groups, like formerly incarcerated adults; and (3) to provide an opportunity for formerly incarcerated adults and graduate nursing students to participate in a dialectical conversation about ethical knowing. Gadamer's writings on practical philosophy, phronesis, and the Socratic dialectic provide the philosophical foundation and framework for the project. The first phase in the project was a 4‐h class within a graduate‐level health promotion course during which 30 nursing students and three formerly incarcerated panelists engaged in a dialectic conversation about what it means to care for formerly incarcerated adults in a meaningful way. After the class, two focus groups were conducted, one with the students and one with the formerly incarcerated panelists. Findings articulated participants' prejudices and assumptions prior to the class, expanded sense of phronesis, and ability to consider nursing practice within a larger ethical framework. Panelists and students left the class with a deeper understanding of one another and expressed an openness towards continued dialectic conversations together. Use of the Socratic dialectic within nursing curricula reflects a current and critical trend in nursing education to bring non‐epistemologic forms of knowledge into the classroom. 相似文献
997.
Due to its intriguing geometry, possessing an open-channel structure, Si24 demonstrates potential for storing and/or transporting Li/Na ions in rechargeable batteries. In this work, first-principles calculations were employed to investigate the phase stability and Li/Na storage and transport properties of the Si24 anode to evaluate its electrochemical performance for batteries. The intercalation of Li and Na into the Si24 structure could deliver a capacity of 159 mA h g−1 (Li4Si24 and Na4Si24), and the average intercalation potentials were 0.17 V (vs. Li) and 0.34 V (vs. Na). Moreover, the volume change of Si24 upon intercalation proved very small (0.09% for Li, 2.81% for Na), indicating its “zero-strain” properties with stable cycling performance. Li+ and Na+ can diffuse along the channels inside the Si24 structure with barrier energies of 0.14 and 0.80 eV respectively, and the ionic conductivity of Li2.66Si24 was calculated to be as high as 1.03 × 10−1 S cm−1 at 300 K. Our calculations indicate that the fast Li-ionic conductivity properties make the Si24 structure a novel anode material for both lithium and sodium ion batteries.Systematic investigation of Si24 for Li/Na ion batteries using first-principles methods. 相似文献
998.
In Young Kim Jang Mee Lee Eui-Ho Hwang Yi-Rong Pei Woo-Bin Jin Jin-Ho Choy Seong-Ju Hwang 《RSC advances》2018,8(32):18109
Correction for ‘Water-floating nanohybrid films of layered titanate–graphene for sanitization of algae without secondary pollution’ by In Young Kim et al., RSC Adv., 2016, 6, 98528–98535.In the published paper, the affiliations of Eui-Ho Hwang and Woo-Bin Jin were wrongly designated, and the corrected version is shown below.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers. 相似文献
999.
Sialic acids are monosaccharides typically found on cell surfaces and attached to soluble proteins, or as essential components of ganglioside structures that play a critical role in brain development and neural transmission. Human milk also contains sialic acid conjugated to oligosaccharides, glycolipids, and glycoproteins. These nutrients can reach the large bowel where they may be metabolised by the microbiota. However, little is known about the members of the microbiota involved in this function. To identify intestinal bacteria that utilise sialic acid within a complex intestinal community, we cultured the caecal microbiota from piglets in the presence of 13C-labelled sialic acid. Using RNA-based stable isotope probing, we identified bacteria that consumed 13C-sialic acid by fractionating total RNA in isopycnic buoyant density gradients followed by 16S rRNA gene analysis. Addition of sialic acid caused significant microbial community changes. A relative rise in Prevotella and Lactobacillus species was accompanied by a corresponding reduction in the genera Escherichia/Shigella, Ruminococcus and Eubacterium. Inspection of isotopically labelled RNA sequences suggests that the labelled sialic acid was consumed by a wide range of bacteria. However, species affiliated with the genus Prevotella were clearly identified as the most prolific users, as solely their RNA showed significantly higher relative shares among the most labelled RNA species. Given the relevance of sialic acid in nutrition, this study contributes to a better understanding of their microbial transformation in the intestinal tract with potential implications for human health. 相似文献
1000.